linux-handhelds-2.6 2.6.21: Move away from nuiltin NFS support, use modular USB gadgets.

linux-handhelds-2.6 2.6.21: Move away from nuiltin NFS support, use modular USB gadgets.
* Now that there's flexible early userspace support in OE (initramfs-uniboot)
which handles NFS booting among other things, there's no longer need to have
NFS boot support in kernel. This gets NFS out of kernel, and frees g_ether
from being compiled into kernel, thus opening road for modular USB gadget
drivers.
* A bit tough move deep into Angstrom RCs, but this was on TODO for long time,
and just yesterday I hit usecase where I was stuck late night with the need
to move data between 2 boxes, with only common interface in both being USB,
but still w/o flashdrive to use. So, I took this opportinity not just
to try g_file_storage, but also handle this issue.